BAEL-1372: Adding jUnits for Testing Netty with EmbeddedChannel article (#3973)

libraries/src/main/java/com/baeldung/netty/CalculatorOperationHandler.java

@@ -0,0 +1,49 @@
+package com.baeldung.netty;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.*;
+import io.netty.util.CharsetUtil;
+
+public class CalculatorOperationHandler extends SimpleChannelInboundHandler<Operation> {
+
+    protected void channelRead0(ChannelHandlerContext ctx, Operation msg) throws Exception {
+        Long result = calculateEndpoint(msg);
+        sendHttpResponse(ctx, new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CREATED), result.toString());
+        ctx.fireChannelRead(result);
+    }
+
+    private long calculateEndpoint(Operation operation) {
+
+        String operator = operation.getOperator().toLowerCase().trim();
+        switch (operator) {
+            case "add":
+                return operation.getNumber1() + operation.getNumber2();
+            case "multiply":
+                return operation.getNumber1() * operation.getNumber2();
+            default:
+                throw new IllegalArgumentException("Operation not defined");
+        }
+    }
+
+    public static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpResponse res, String content) {
+
+        // Generate an error page if response getStatus code is not OK (200).
+        ByteBuf buf = Unpooled.copiedBuffer(content, CharsetUtil.UTF_8);
+        res.content().writeBytes(buf);
+
+        HttpUtil.setContentLength(res, res.content().readableBytes());
+
+        ctx.channel().writeAndFlush(res);
+    }
+
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
+            throws Exception {
+
+        sendHttpResponse(ctx, new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.INTERNAL_SERVER_ERROR), "Operation not defined");
+        ctx.fireExceptionCaught(cause);
+    }
+
+}

libraries/src/main/java/com/baeldung/netty/HttpMessageHandler.java

@@ -0,0 +1,40 @@
+package com.baeldung.netty;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpMethod;
+
+public class HttpMessageHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
+
+    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
+
+        String uri = msg.uri();
+        HttpMethod httpMethod = msg.method();
+        HttpHeaders headers = msg.headers();
+
+        if (HttpMethod.GET == httpMethod) {
+
+            String[] uriComponents = uri.split("[?]");
+            String endpoint = uriComponents[0];
+            String[] queryParams = uriComponents[1].split("&");
+
+            if ("/calculate".equalsIgnoreCase(endpoint)) {
+
+                String[] firstQueryParam = queryParams[0].split("=");
+                String[] secondQueryParam = queryParams[1].split("=");
+
+                Integer a = Integer.valueOf(firstQueryParam[1]);
+                Integer b = Integer.valueOf(secondQueryParam[1]);
+                String operator = headers.get("operator");
+
+                Operation operation = new Operation(a, b, operator);
+                ctx.fireChannelRead(operation);
+            }
+        } else {
+            throw new UnsupportedOperationException("HTTP method not supported");
+        }
+
+    }
+}

libraries/src/main/java/com/baeldung/netty/Operation.java

@@ -0,0 +1,49 @@
+package com.baeldung.netty;
+
+import java.io.Serializable;
+
+public class Operation implements Serializable {
+
+    private Integer number1;
+    private Integer number2;
+    private String operator;
+
+    public Operation(Integer number1, Integer number2, String operator) {
+        this.number1 = number1;
+        this.number2 = number2;
+        this.operator = operator;
+    }
+
+    public Integer getNumber1() {
+        return number1;
+    }
+
+    public void setNumber1(Integer number1) {
+        this.number1 = number1;
+    }
+
+    public Integer getNumber2() {
+        return number2;
+    }
+
+    public void setNumber2(Integer number2) {
+        this.number2 = number2;
+    }
+
+    public String getOperator() {
+        return operator;
+    }
+
+    public void setOperator(String operator) {
+        this.operator = operator;
+    }
+
+    @Override
+    public String toString() {
+        return "Operation{" +
+                "number1=" + number1 +
+                ", number2=" + number2 +
+                ", operator='" + operator + '\'' +
+                '}';
+    }
+}